In recent years, it has been desired to efficiently culture a large amount of cells, tissue, microorganisms, or the like in an artificial environment in the fields of drug production, gene therapy, regenerative medicine, immunotherapy, and the like.
A culture vessel (culture bag) may be charged with cells and a culture medium, and the cells may be automatically cultured in large quantities in the closed system.
Such a culture vessel is required to exhibit gas permeability and durability necessary for cell culture, heat-seal strength necessary for forming a bag, and the like, and has been formed using a polyolefin resin that exhibits these properties.
When using a culture vessel that is formed of a polyolefin resin, floating cells can be easily cultured, but it has been difficult to efficiently culture adherent cells that require a vessel wall or the like as a scaffold during culture. Specifically, it is necessary for the culture surface to have moderate wettability and hydrophilicity in order to allow adherent cells to adhere to the wall of the culture vessel. However, since the surface of a culture vessel formed of a polyolefin resin is hydrophobic, adherent cells cannot sufficiently adhere to the culture surface, and it has been difficult to achieve high proliferation efficiency.
In order to solve the above problem, a technique that subjects the culture surface of a film that forms a culture vessel to a hydrophilization treatment using a corona discharge method (see Patent Document 1) or a UV-ozone method (see Patent Documents 2 and 3) before forming a culture vessel in the shape of a bag has been proposed.
Patent Document 1: JP-A-6-98756
Patent Document 2: JP-A-2009-27944
Patent Document 3: JP-A-2009-27945